Terminal and method for transmitting signal in wireless communication system

ABSTRACT

An embodiment of the present invention provides a method for transmitting a signal by a terminal in a wireless communication system, the method comprising a step of the terminal selecting a transmission resource, and a step of the terminal transmitting the signal to another terminal by using the selected transmission resource, wherein the transmission resource includes a first transmission resource range for transmission of the first signal, and a second transmission resource range for transmission of a second signal and wider than the first transmission resource range, wherein the first transmission resource range and the second transmission resource range are mapped onto different subchannel indices, and the first transmission resource range is allocated to an edge of a frequency range for the transmission of the first signal and the second signal.

TECHNICAL FIELD

The present disclosure relates to a wireless communication system and,more particularly, to a method and terminal for transmitting a signal.

BACKGROUND ART

As more and more communication devices demand larger communicationcapacities, the need for enhanced mobile broadband communicationrelative to the legacy radio access technologies (RATs) has emerged.Massive machine type communication (mMTC) that provides various servicesby interconnecting multiple devices and things irrespective of time andplace is also one of main issues to be addressed for future-generationcommunications. A communication system design considering services/userequipments (UEs) sensitive to reliability and latency is underdiscussion as well. As such, the introduction of a future-generation RATconsidering enhanced mobile broadband (eMBB), mMTC, ultra-reliabilityand low latency communication (URLLC), and so on is being discussed. Forconvenience, this technology is referred to as new RAT (NR) in thepresent disclosure. NR is an exemplary 5th generation (5G) RAT.

A new RAT system including NR adopts orthogonal frequency divisionmultiplexing (OFDM) or a similar transmission scheme. The new RAT systemmay use OFDM parameters different from long term evolution (LTE) OFDMparameters. Further, the new RAT system may have a larger systembandwidth (e.g., 100 MHz), while following the legacy LTE/LTE-advanced(LTE-A) numerology. Further, one cell may support a plurality ofnumerologies in the new RAT system. That is, UEs operating withdifferent numerologies may co-exist within one cell.

Vehicle-to-everything (V2X) is a communication technology of exchanginginformation between a vehicle and another vehicle, a pedestrian, orinfrastructure. V2X may cover four types of communications such asvehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I),vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). V2Xcommunication may be provided via a PC5 interface and/or a Uu interface.

DISCLOSURE Technical Problem

The present disclosure proposes a method of preventing/reducing aphenomenon (resource fragmentation) that transmission of a large packetis disturbed when a specific UE partially occupies resource(s) in ascheduling mode in which UEs autonomously select resources for directcommunication therebetween.

It will be appreciated by persons skilled in the art that the objectsthat could be achieved with the present disclosure are not limited towhat has been particularly described hereinabove and the above and otherobjects that the present disclosure could achieve will be more clearlyunderstood from the following detailed description.

Technical Solution

In one aspect of the present disclosure, a method of transmitting asignal by a user equipment (UE) in a wireless communication system isprovided. The method may include: selecting, by the UE, a transmissionresource; and transmitting the signal on the selected transmissionresource to another UE. The transmission resource may include a firsttransmission resource region for transmission of a first signal and asecond transmission resource region for transmission of a second signal,wherein the second transmission resource region may be greater than thefirst transmission resource region. The first and second transmissionresource regions may be mapped to different subchannel indices. Thefirst transmission resource region may be allocated to edges of afrequency region for transmitting the first and second signals.

The first transmission resource region may be mapped to a subchannelindex greater than a first threshold or smaller than a second threshold,and the second transmission resource region may be mapped to asubchannel index smaller than or equal to the first threshold andgreater than or equal to the second threshold. The first threshold maybe greater than the second threshold.

The first transmission resource region may be mapped to a minimumsubchannel index and a maximum subchannel index, and the secondtransmission resource region may be mapped to a subchannel index exceptthe minimum and maximum subchannel indices.

Transmitting the signal may include: when an amount of resources fortransmitting the signal is greater than or equal to a third threshold,transmitting the signal as the second signal in the second resourceregion; and when the amount of resources for transmitting the signal issmaller than the third threshold, transmitting the signal as the firstsignal in the first resource region.

The method may further include, when the first transmission resourceregion overlaps with the second transmission resource region, droppingthe transmission of the first signal or reselecting the firsttransmission resource.

The method may further include configuring and transmitting a time gapbetween control and data signals for the second signal.

The first and second transmission resource regions may be configuredwithin a resource pool for transmission of a sidelink signal.

The first signal may be a narrowband signal, and the second signal maybe a wideband signal.

In another aspect of the present disclosure, a UE for transmitting asignal in a wireless communication system is provided. The UE mayinclude a transceiver and a processor. The processor may be configuredto: select a transmission resource; and transmit the signal on theselected transmission resource to another UE. The transmission resourcemay include a first transmission resource region for transmission of afirst signal and a second transmission resource region for transmissionof a second signal, wherein the second transmission resource region maybe greater than the first transmission resource region. The first andsecond transmission resource regions may be mapped to differentsubchannel indices. The first transmission resource region may beallocated to edges of a frequency region for transmitting the first andsecond signals.

Advantageous Effects

According to the present disclosure, a user equipment (UE) may beprohibited from selecting resources indiscreetly

The present disclosure may provide a wireless communication system wherea UE easily secures a transmission resource when the UE is configuredwith wideband transmission.

According to the present disclosure, a wideband transmission UE mayperform transmission by applying a time gap between a physical sidelinkcontrol channel (PSCCH) and a physical sidelink shared channel (PSSCH)so that a narrowband transmission UE may efficiently detect (check) thatnarrowband transmission overlaps with wideband transmission.

According to the present disclosure, the sensing complexity of a UE maybe reduced by dividing resource regions.

It will be appreciated by persons skilled in the art that the effectsthat can be achieved with the present disclosure are not limited to whathas been particularly described hereinabove and other advantages of thepresent disclosure will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure, provide embodiments of the presentdisclosure together with detail explanation. Yet, a technicalcharacteristic of the present disclosure is not limited to a specificdrawing. Characteristics disclosed in each of the drawings are combinedwith each other to configure a new embodiment. Reference numerals ineach drawing correspond to structural elements.

FIG. 1 illustrates a frame structure in new radio (NR)

FIG. 2 illustrates a resource grid in NR.

FIG. 3 illustrates sidelink synchronization.

FIG. 4 illustrates a time resource unit for transmitting a sidelinksynchronization signal.

FIG. 5 illustrates a sidelink resource pool.

FIG. 6 illustrates scheduling schemes based on sidelink transmissionmodes.

FIG. 7 illustrates selection of sidelink transmission resources.

FIG. 8 illustrates transmission of a physical sidelink control channel(PSCCH).

FIG. 9 illustrates PSCCH transmission in sidelink vehicle-to-everything(V2X) communication.

FIG. 10 is a flowchart illustrating operations of a method according tothe embodiments of the present disclosure.

FIG. 11 is a flowchart illustrating operations of a method according tothe embodiments of the present disclosure.

FIG. 12 is a diagram showing a communication system to which oneembodiment of the present disclosure is applied.

FIG. 13 is a block diagram showing a wireless device to which oneembodiment of the present disclosure is applicable.

FIG. 14 is a diagram showing a signal processing circuit for atransmission signal to which one embodiment of the present disclosure isapplicable.

FIG. 15 is a block diagram showing a wireless device to which anotherembodiment of the present disclosure is applicable.

FIG. 16 is a block diagram showing a portable device to which anotherembodiment of the present disclosure is applicable.

FIG. 17 is a block diagram showing a vehicle or an autonomous vehicle towhich another embodiment of the present disclosure is applicable.

FIG. 18 is a diagram showing a vehicle to which another embodiment ofthe present disclosure is applicable.

BEST MODE

In this document, downlink (DL) communication refers to communicationfrom a base station (BS) to a user equipment (UE), and uplink (UL)communication refers to communication from the UE to the BS. In DL, atransmitter may be a part of the BS and a receiver may be a part of theUE. In UL, a transmitter may be a part of the UE and a receiver may be apart of the BS. Herein, the BS may be referred to as a firstcommunication device, and the UE may be referred to as a secondcommunication device. The term ‘BS’ may be replaced with ‘fixedstation’, ‘Node B’, ‘evolved Node B (eNB)’, ‘next-generation node B(gNB)’, ‘base transceiver system (BTS)’, ‘access point (AP)’, ‘networknode’, ‘fifth-generation (5G) network node’, ‘artificial intelligence(AI) system’, ‘road side unit (RSU)’, ‘robot’, etc. The term ‘UE’ may bereplaced with ‘terminal’, ‘mobile station (MS)’, ‘user terminal (UT)’,‘mobile subscriber station (MSS)’, ‘subscriber station (SS)’, ‘advancedmobile station (AMS)’, ‘wireless terminal (WT)’, ‘machine typecommunication (MTC) device’, ‘machine-to-machine (M2M) device’,‘device-to-device (D2D) device’, ‘vehicle’, ‘robot’, ‘AI module’, etc.

The technology described herein is applicable to various wireless accesssystems such as code division multiple access (CDMA), frequency divisionmultiple access (FDMA), time division multiple access (TDMA), orthogonalfrequency division multiple access (OFDMA), single carrier frequencydivision multiple access (SC-FDMA), etc. The CDMA may be implemented asradio technology such as universal terrestrial radio access (UTRA) orCDMA2000. The TDMA may be implemented as radio technology such as globalsystem for mobile communications (GSM), general packet radio service(GPRS), or enhanced data rates for GSM evolution (EDGE). The OFDMA maybe implemented as radio technology such as the Institute of Electricaland Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX),IEEE 802-20, evolved UTRA (E-UTRA), etc. The UTRA is a part of auniversal mobile telecommunication system (UMTS). 3rd generationpartnership project (3GPP) long term evolution (LTE) is a part ofevolved UMTS (E-UMTS) using E-UTRA. LTE-advance (LTE-A) or LTE-A pro isan evolved version of 3GPP LTE. 3GPP new radio or new radio accesstechnology (3GPP NR) is an evolved version of 3GPP LTE, LTE-A, or LTE-Apro.

Although the present disclosure is described based on 3GPP communicationsystems (e.g., LTE-A, NR, etc.) for clarity of description, the spiritof the present disclosure is not limited thereto. LTE refers totechnologies beyond 3GPP technical specification (TS) 36.xxx Release 8.In particular, LTE technologies beyond 3GPP TS 36.xxx Release 10 arereferred to as LTE-A, and LTE technologies beyond 3GPP TS 36.xxx Release13 are referred to as LTE-A pro. 3GPP NR refers to technologies beyond3GPP TS 38.xxx Release 15. LTE/NR may be called ‘3GPP system’. Herein,“xxx” refers to a standard specification number.

In the present disclosure, a node refers to a fixed point capable oftransmitting/receiving a radio signal for communication with a UE.Various types of BSs may be used as the node regardless of the namesthereof. For example, the node may include a BS, a node B (NB), an eNB,a pico-cell eNB (PeNB), a home eNB (HeNB), a relay, a repeater, etc. Adevice other than the BS may be the node. For example, a radio remotehead (RRH) or a radio remote unit (RRU) may be the node. The RRH or RRUgenerally has a lower power level than that of the BS. At least oneantenna is installed for each node. The antenna may refer to a physicalantenna or mean an antenna port, a virtual antenna, or an antenna group.The node may also be referred to as a point.

In the present disclosure, a cell refers to a prescribed geographicalarea in which one or more nodes provide communication services or aradio resource. When a cell refers to a geographical area, the cell maybe understood as the coverage of a node where the node is capable ofproviding services using carriers. When a cell refers to a radioresource, the cell may be related to a bandwidth (BW), i.e., a frequencyrange configured for carriers. Since DL coverage, a range within whichthe node is capable of transmitting a valid signal, and UL coverage, arange within which the node is capable of receiving a valid signal fromthe UE, depend on carriers carrying the corresponding signals, thecoverage of the node may be related to the coverage of the cell, i.e.,radio resource used by the node. Accordingly, the term “cell” may beused to indicate the service coverage of a node, a radio resource, or arange to which a signal transmitted on a radio resource can reach withvalid strength.

In the present disclosure, communication with a specific cell may meancommunication with a BS or node that provides communication services tothe specific cell. In addition, a DL/UL signal in the specific cellrefers to a DL/UL signal from/to the BS or node that providescommunication services to the specific cell. In particular, a cellproviding DL/UL communication services to a UE may be called a servingcell. The channel state/quality of the specific cell may refer to thechannel state/quality of a communication link formed between the BS ornode, which provides communication services to the specific cell, andthe UE.

When a cell is related to a radio resource, the cell may be defined as acombination of DL and UL resources, i.e., a combination of DL and ULcomponent carriers (CCs). The cell may be configured to include only DLresources or a combination of DL and UL resources. When carrieraggregation is supported, a linkage between the carrier frequency of aDL resource (or DL CC) and the carrier frequency of a UL resource (or ULCC) may be indicated by system information transmitted on acorresponding cell. The carrier frequency may be equal to or differentfrom the center frequency of each cell or CC. A cell operating on aprimary frequency may be referred to as a primary cell (PCell) or PCC,and a cell operating on a secondary frequency may be referred to as asecondary cell (SCell) or SCC. The SCell may be configured after the UEand BS establish a radio resource control (RRC) connection therebetweenby performing an RRC connection establishment procedure, that is, afterthe UE enters the RRC_CONNECTED state. The RRC connection may mean apath that enables the RRC of the UE and the RRC of the BS to exchange anRRC message. The SCell may be configured to provide additional radioresources to the UE. The SCell and the PCell may form a set of servingcells for the UE depending on the capabilities of the UE. When the UE isnot configured with carrier aggregation or does not support the carrieraggregation although the UE is in the RRC_CONNECTED state, only oneserving cell configured with the PCell exists.

A cell supports a unique radio access technology (RAT). For example,transmission/reception in an LTE cell is performed based on the LTE RAT,and transmission/reception in a 5G cell is performed based on the 5GRAT.

The carrier aggregation is a technology for combining a plurality ofcarriers each having a system BW smaller than a target BW to supportbroadband. The carrier aggregation is different from OFDMA in that inthe former, DL or UL communication is performed on a plurality ofcarrier frequencies each forming a system BW (or channel BW) and in thelatter, DL or UL communication is performed by dividing a base frequencyband into a plurality of orthogonal subcarriers and loading thesubcarriers in one carrier frequency. For example, in OFDMA ororthogonal frequency division multiplexing (OFDM), one frequency bandwith a predetermined system BW is divided into a plurality ofsubcarriers with a predetermined subcarrier spacing, andinformation/data is mapped to the plurality of subcarriers. Frequencyup-conversion is applied to the frequency band to which theinformation/data is mapped, and the information/data is transmitted onthe carrier frequency in the frequency band. In wireless carrieraggregation, multiple frequency bands, each of which has its own systemBW and carrier frequency, may be simultaneously used for communication,and each frequency band used in the carrier aggregation may be dividedinto a plurality of subcarriers with a predetermined subcarrier spacing.

3GPP communication specifications define DL physical channelscorresponding to resource elements carrying information originating fromhigher (upper) layers of physical layers (e.g., a medium access control(MAC) layer, a radio link control (RLC) layer, a protocol dataconvergence protocol (PDCP) layer, an RRC layer, a service dataadaptation protocol (SDAP) layer, a non-access stratum (NAS) layer,etc.) and DL physical signals corresponding to resource elements whichare used by physical layers but do not carry information originatingfrom higher layers. For example, a physical downlink shared channel(PDSCH), a physical broadcast channel (PBCH), a physical multicastchannel (PMCH), a physical control format indicator channel (PCFICH),and a physical downlink control channel (PDCCH) are defined as the DLphysical channels, and a reference signal and a synchronization signalare defined as the DL physical signals. A reference signal (RS), whichis called a pilot signal, refers to a predefined signal with a specificwaveform known to both the BS and UE. For example, a cell-specific RS(CRS), a UE-specific RS (UE-RS), a positioning RS (PRS), a channel stateinformation RS (CSI-RS), and a demodulation reference signal (DMRS) maybe defined as DL RSs. In addition, the 3GPP communication specificationsdefine UL physical channels corresponding to resource elements carryinginformation originating from higher layers and UL physical signalscorresponding to resource elements which are used by physical layers butdo not carry information originating from higher layers. For example, aphysical uplink shared channel (PUSCH), a physical uplink controlchannel (PUCCH), and a physical random access channel (PRACH) aredefined as the UL physical channels, and a demodulation reference signal(DMRS) for a UL control/data signal and a sounding reference signal(SRS) used for UL channel measurement are defined as the UL physicalsignals.

In the present disclosure, the PDCCH and the PDSCH may refer to a set oftime-frequency resources or resource elements carrying downlink controlinformation (DCI) of the physical layer and a set of time-frequencyresources or resource elements carrying DL data thereof, respectively.The PUCCH, the PUSCH, and the PRACH may refer to a set of time-frequencyresources or resource elements carrying uplink control information (UCI)of the physical layer, a set of time-frequency resources or resourceelements carrying UL data thereof, and a set of time-frequency resourcesor resource elements carrying random access signals thereof,respectively. When it is said that a UE transmits a UL physical channel(e.g., PUCCH, PUSCH, PRACH, etc.), it may mean that the UE transmitsDCI, UL data, or a random access signal on or over the corresponding ULphysical channel When it is said that the BS receives a UL physicalchannel, it may mean that the BS receives DCI, UL data, a random accesssignal on or over the corresponding UL physical channel When it is saidthat the BS transmits a DL physical channel (e.g., PDCCH, PDSCH, etc.),it may mean that the BS transmits DCI or UL data on or over thecorresponding DL physical channel When it is said that the UE receives aDL physical channel, it may mean that the UE receives DCI or UL data onor over the corresponding DL physical channel

In the present disclosure, a transport block may mean the payload forthe physical layer. For example, data provided from the higher layer orMAC layer to the physical layer may be referred to as the transportblock.

In the present disclosure, hybrid automatic repeat request (HARQ) maymean a method used for error control. A HARQ acknowledgement (HARQ-ACK)transmitted in DL is used to control an error for UL data, and aHARQ-ACK transmitted in UL is used to control an error for DL data. Atransmitter that performs the HARQ operation waits for an ACK signalafter transmitting data (e.g. transport blocks or codewords). A receiverthat performs the HARQ operation transmits an ACK signal only when thereceiver correctly receives data. If there is an error in the receiveddata, the receiver transmits a negative ACK (NACK) signal. Uponreceiving the ACK signal, the transmitter may transmit (new) data but,upon receiving the NACK signal, the transmitter may retransmit the data.Meanwhile, there may be a time delay until the BS receives ACK/NACK fromthe UE and retransmits data after transmitting scheduling informationand data according to the scheduling information. The time delay occursdue to a channel propagation delay or a time required for datadecoding/encoding. Accordingly, if new data is transmitted aftercompletion of the current HARQ process, there may be a gap in datatransmission due to the time delay. To avoid such a gap in datatransmission during the time delay, a plurality of independent HARQprocesses are used. For example, when there are 7 transmission occasionsbetween initial transmission and retransmission, a communication devicemay perform data transmission with no gap by managing 7 independent HARQprocesses. When the communication device uses a plurality of parallelHARQ processes, the communication device may successively perform UL/DLtransmission while waiting for HARQ feedback for previous UL/DLtransmission.

In the present disclosure, CSI collectively refers to informationindicating the quality of a radio channel (also called a link) createdbetween a UE and an antenna port. The CSI includes at least one of achannel quality indicator (CQI), a precoding matrix indicator (PMI), aCSI-RS resource indicator (CRI), an SSB resource indicator (SSBRI), alayer indicator (LI), a rank indicator (RI), or a reference signalreceived power (RSRP).

In the present disclosure, frequency division multiplexing (FDM) maymean that signals/channels/users are transmitted/received on differentfrequency resources, and time division multiplexing (TDM) may mean thatsignals/channels/users are transmitted/received on different timeresources.

In the present disclosure, frequency division duplex (FDD) refers to acommunication scheme in which UL communication is performed on a ULcarrier and DL communication is performed on a DL carrier linked to theUL carrier, and time division duplex (TDD) refers to a communicationscheme in which UL and DL communication are performed by splitting time.

The details of the background, terminology, abbreviations, etc. usedherein may be found in documents published before the presentdisclosure. For example, 3GPP TS 24 series, 3GPP TS 34 series, and 3GPPTS 38 series may be referenced(http://www.3gpp.org/specifications/specification-numbering).

Frame Structure

FIG. 1 is a diagram illustrating a frame structure in NR.

The NR system may support multiple numerologies. The numerology isdefined by a subcarrier spacing and cyclic prefix (CP) overhead. Aplurality of subcarrier spacings may be derived by scaling a basicsubcarrier spacing by an integer N (or μ). The numerology may beselected independently of the frequency band of a cell although it isassumed that a small subcarrier spacing is not used at a high carrierfrequency. In addition, the NR system may support various framestructures based on the multiple numerologies.

Hereinafter, an OFDM numerology and a frame structure, which may beconsidered in the NR system, will be described. Table 1 shows multipleOFDM numerologies supported in the NR system. The value of μ for abandwidth part and a CP may be obtained by RRC parameters provided bythe BS.

TABLE 1 μ Δf = 2^(μ)*15 [kHz] Cyclic prefix(CP) 0 15 Normal 1 30 Normal2 60 Normal, Extended 3 120 Normal 4 240 Normal

The NR system supports multiple numerologies (e.g., subcarrier spacings)to support various 5G services. For example, the NR system supports awide area in conventional cellular bands in a subcarrier spacing of 15kHz and supports a dense urban environment, low latency, and widecarrier BW in a subcarrier spacing of 30/60 kHz. In a subcarrier spacingof 60 kHz or above, the NR system supports a BW higher than 24.25 GHz toovercome phase noise.

Resource Grid

FIG. 2 illustrates a resource grid in the NR.

Referring to FIG. 2, a resource grid consisting of Nsize,μgrid*NRBscsubcarriers and 14*2 μ OFDM symbols may be defined for each subcarrierspacing configuration and carrier, where Nsize,μgrid is indicated by RRCsignaling from the BS. Nsize,μgrid may vary not only depending on thesubcarrier spacing configuration μ but also between UL and DL. Oneresource grid exists for the subcarrier spacing configuration μ, anantenna port p, and a transmission direction (i.e., UL or DL). Eachelement in the resource gird for the subcarrier spacing configuration μand the antenna port p may be referred to as a resource element andidentified uniquely by an index pair of (k, l), where k denotes an indexin the frequency domain and l denotes the relative location of a symbolin the frequency domain with respect to a reference point. The resourceelement (k, l) for the subcarrier spacing configuration μ and theantenna port p may be a physical resource and a complex value,a(p,μ)k,l. A resource block (RB) is defined as NRBsc consecutivesubcarriers in the frequency domain (where NRBsc=12).

Considering that the UE is incapable of supporting a wide BW supportedin the NR system, the UE may be configured to operate in a part of thefrequency BW of a cell (hereinafter referred to as a bandwidth part(BWP)).

Bandwidth Part (BWP)

The NR system may support up to 400 MHz for each carrier. If the UEalways keeps a radio frequency (RF) module on for all carriers whileoperating on such a wideband carrier, the battery consumption of the UEmay increase. Considering multiple use cases (e.g., eMBB, URLLC, mMTC,V2X, etc.) operating in one wideband carrier, a different numerology(e.g., subcarrier spacing) may be supported for each frequency band ofthe carrier. Further, considering that each UE may have a differentcapability regarding the maximum BW, the BS may instruct the UE tooperate only in a partial BW rather than the whole BW of the widebandcarrier. The partial bandwidth is referred to as the BWP. The BWP is asubset of contiguous common RBs defined for numerology pi in BWP i ofthe carrier in the frequency domain, and one numerology (e.g.,subcarrier spacing, CP length, and/or slot/mini-slot duration) may beconfigured for the BWP.

The BS may configure one or more BWPs in one carrier configured for theUE. Alternatively, if UEs are concentrated in a specific BWP, the BS maymove some UEs to another BWP for load balancing. For frequency-domaininter-cell interference cancellation between neighbor cells, the BS mayconfigure BWPs on both sides of a cell except for some central spectrain the whole BW in the same slot. That is, the BS may configure at leastone DL/UL BWP for the UE associated with the wideband carrier, activateat least one of DL/UL BWP(s) configured at a specific time (by L2signaling which is a physical-layer control signal, a MAC controlelement (CE) which is a MAC-layer control signal, or RRC signaling),instruct the UE to switch to another configured DL/UL BWP (by L1signaling, a MAC CE, or RRC signaling), or set a timer value and switchthe UE to a predetermined DL/UL BWP upon expiration of the timer value.In particular, an activated DL/UL BWP is referred to as an active DL/ULBWP. While performing initial access or before setting up an RRCconnection, the UE may not receive a DL/UL BWP configuration. A DL/ULBWP that the UE assumes in this situation is referred to as an initialactive DL/UL BWP.

Synchronization Acquisition of Sidelink UE

In time division multiple access (TDMA) and frequency division multipleaccess (FDMA) systems, accurate time and frequency synchronization isessential. If time and frequency synchronization is not accurate,inter-symbol interference (ISI) and inter-carrier interference (ICI) mayoccur so that system performance may be degraded. This may occur in V2X.For time/frequency synchronization in V2X, a sidelink synchronizationsignal (SLSS) may be used in the physical layer, and master informationblock-sidelink-V2X (MIB-SL-V2X) may be used in the RLC layer.

FIG. 3 illustrates a synchronization source and a synchronizationreference in V2X.

Referring to FIG. 3, in V2X, a UE may be directly synchronized to globalnavigation satellite systems (GNSS) or indirectly synchronized to theGNSS through another UE (in or out of the network coverage) that isdirectly synchronized to the GNSS. When the GNSS is set to thesynchronization source, the UE may calculate a direct frame number (DFN)and a subframe number based on coordinated universal time (UTC) and a(pre)configured DFN offset.

Alternatively, the UE may be directly synchronized to the BS orsynchronized to another UE that is time/frequency synchronized to theBS. For example, if the UE is in the coverage of the network, the UE mayreceive synchronization information provided by the BS and be directlysynchronized to the BS. Thereafter, the UE may provide thesynchronization information to another adjacent UE. If the timing of theBS is set to the synchronization reference, the UE may follow a cellassociated with a corresponding frequency (if the UE is in the cellcoverage at the corresponding frequency) or follow a PCell or servingcell (if the UE is out of the cell coverage at the correspondingfrequency) for synchronization and DL measurement.

The serving cell (BS) may provide a synchronization configuration forcarriers used in V2X sidelink communication. In this case, the UE mayfollow the synchronization configuration received from the BS. If the UEdetects no cell from the carriers used in the V2X sidelink communicationand receives no synchronization configuration from the serving cell, theUE may follow a predetermined synchronization configuration.

Alternatively, the UE may be synchronized to another UE that fails todirectly or indirectly obtain the synchronization information from theBS or GNSS. The synchronization source and preference may bepreconfigured for the UE or configured in a control message from the BS.

Hereinbelow, the SLSS and synchronization information will be described.

The SLSS may be a sidelink-specific sequence and include a primarysidelink synchronization signal (PSSS) and a secondary sidelinksynchronization signal (SSSS).

Each SLSS may have a physical layer sidelink synchronization identity(ID), and the value may be, for example, any of 0 to 335. Thesynchronization source may be identified depending on which of the abovevalues is used. For example, 0, 168, and 169 may indicate the GNSS, 1 to167 may indicate the BS, and 170 to 335 may indicate out-of-coverage.Alternatively, among the values of the physical layer sidelinksynchronization ID, 0 to 167 may be used by the network, and 168 to 335may be used for the out-of-coverage state.

FIG. 4 illustrates a time resource unit for SLSS transmission. The timeresource unit may be a subframe in LTE/LTE-A and a slot in 5G. Thedetails may be found in 3GPP TS 36 series or 3GPP TS 28 series. Aphysical sidelink broadcast channel (PSBCH) may refer to a channel forcarrying (broadcasting) basic (system) information that the UE needs toknow before sidelink signal transmission and reception (e.g.,SLSS-related information, a duplex mode (DM), a TDD UL/DL configuration,information about a resource pool, the type of an SLSS-relatedapplication, a subframe offset, broadcast information, etc.). The PSBCHand SLSS may be transmitted in the same time resource unit, or the PSBCHmay be transmitted in a time resource unit after that in which the SLSSis transmitted. A DMRS may be used to demodulate the PSBCH.

Sidelink Transmission Mode

For sidelink communication, transmission modes 1, 2, 3 and 4 are used.

In transmission mode 1/3, the BS performs resource scheduling for UE 1over a PDCCH (more specifically, DCI) and UE 1 performs D2D/V2Xcommunication with UE 2 according to the corresponding resourcescheduling. After transmitting sidelink control information (SCI) to UE2 over a physical sidelink control channel (PSCCH), UE 1 may transmitdata based on the SCI over a physical sidelink shared channel (PSSCH).Transmission modes 1 and 3 may be applied to D2D and V2X, respectively.

Transmission mode 2/4 may be a mode in which the UE performs autonomousscheduling (self-scheduling). Specifically, transmission mode 2 isapplied to D2D. The UE may perform D2D operation by autonomouslyselecting a resource from a configured resource pool. Transmission mode4 is applied to V2X. The UE may perform V2X operation by autonomouslyselecting a resource from a selection window through a sensing process.After transmitting the SCI to UE 2 over the PSCCH, UE 1 may transmitdata based on the SCI over the PSSCH. Hereinafter, the term‘transmission mode’ may be simply referred to as ‘mode’.

Control information transmitted by a BS to a UE over a PDCCH may bereferred to as DCI, whereas control information transmitted by a UE toanother UE over a PSCCH may be referred to as SCI. The SCI may carrysidelink scheduling information. The SCI may have several formats, forexample, SCI format 0 and SCI format 1.

SCI format 0 may be used for scheduling the PSSCH. SCI format 0 mayinclude a frequency hopping flag (1 bit), a resource block allocationand hopping resource allocation field (the number of bits may varydepending on the number of sidelink RBs), a time resource pattern (7bits), a modulation and coding scheme (MCS) (5 bits), a time advanceindication (11 bits), a group destination ID (8 bits), etc.

SCI format 1 may be used for scheduling the PSSCH. SCI format 1 mayinclude a priority (3 bits), a resource reservation (4 bits), thelocation of frequency resources for initial transmission andretransmission (the number of bits may vary depending on the number ofsidelink subchannels), a time gap between initial transmission andretransmission (4 bits), an MCS (5 bits), a retransmission index (1bit), a reserved information bit, etc. Hereinbelow, the term ‘reservedinformation bit’ may be simply referred to as ‘reserved bit’ . Thereserved bit may be added until the bit size of SCI format 1 becomes 32bits.

SCI format 0 may be used for transmission modes 1 and 2, and SCI format1 may be used for transmission modes 3 and 4.

Sidelink Resource Pool

FIG. 5 shows an example of a first UE (UE1), a second UE (UE2) and aresource pool used by UE1 and UE2 performing sidelink communication.

In FIG. 5(a), a UE corresponds to a terminal or such a network device asa BS transmitting and receiving a signal according to a sidelinkcommunication scheme. A UE selects a resource unit corresponding to aspecific resource from a resource pool corresponding to a set ofresources and the UE transmits a sidelink signal using the selectedresource unit. UE2 corresponding to a receiving UE receives aconfiguration of a resource pool in which UE1 is able to transmit asignal and detects a signal of UE1 in the resource pool. In this case,if UE1 is located in the coverage of a BS, the BS may inform UE1 of theresource pool. If UE1 is located out of the coverage of the BS, theresource pool may be informed by a different UE or may be determined bya predetermined resource. In general, a resource pool includes aplurality of resource units. A UE selects one or more resource unitsfrom among a plurality of the resource units and may be able to use theselected resource unit(s) for sidelink signal transmission. FIG. 5(b)shows an example of configuring a resource unit. Referring to FIG. 8(b),the entire frequency resources are divided into the NF number ofresource units and the entire time resources are divided into the NTnumber of resource units. In particular, it is able to define NF*NTnumber of resource units in total. In particular, a resource pool may berepeated with a period of NT subframes. Specifically, as shown in FIG.8, one resource unit may periodically and repeatedly appear.Alternatively, an index of a physical resource unit to which a logicalresource unit is mapped may change with a predetermined patternaccording to time to obtain a diversity gain in time domain and/orfrequency domain. In this resource unit structure, a resource pool maycorrespond to a set of resource units capable of being used by a UEintending to transmit a sidelink signal.

A resource pool may be classified into various types. First of all, theresource pool may be classified according to contents of a sidelinksignal transmitted via each resource pool. For example, the contents ofthe sidelink signal may be classified into various signals and aseparate resource pool may be configured according to each of thecontents. The contents of the sidelink signal may include a schedulingassignment (SA or physical sidelink control channel (PSCCH)), a sidelinkdata channel, and a discovery channel. The SA may correspond to a signalincluding information on a resource position of a sidelink data channel,information on a modulation and coding scheme (MCS) necessary formodulating and demodulating a data channel, information on a MIMOtransmission scheme, information on a timing advance (TA), and the like.The SA signal may be transmitted on an identical resource unit in amanner of being multiplexed with sidelink data. In this case, an SAresource pool may correspond to a pool of resources that an SA andsidelink data are transmitted in a manner of being multiplexed. The SAsignal may also be referred to as a sidelink control channel or aphysical sidelink control channel (PSCCH). The sidelink data channel(or, physical sidelink shared channel (PSSCH)) corresponds to a resourcepool used by a transmitting UE to transmit user data. If an SA and asidelink data are transmitted in a manner of being multiplexed in anidentical resource unit, sidelink data channel except SA information maybe transmitted only in a resource pool for the sidelink data channel Inother word, REs, which are used to transmit SA information in a specificresource unit of an SA resource pool, may also be used for transmittingsidelink data in a sidelink data channel resource pool. The discoverychannel may correspond to a resource pool for a message that enables aneighboring UE to discover transmitting UE transmitting information suchas ID of the UE, and the like.

Despite the same contents, sidelink signals may use different resourcepools according to the transmission and reception properties of thesidelink signals. For example, despite the same sidelink data channelsor the same discovery messages, they may be distinguished by differentresource pools according to transmission timing determination schemesfor the sidelink signals (e.g., whether a sidelink signal is transmittedat the reception time of a synchronization reference signal or at a timeresulting from applying a predetermined TA to the reception time of thesynchronization reference signal), resource allocation schemes for thesidelink signals (e.g., whether a BS configures the transmissionresources of an individual signal for an individual transmitting UE orthe individual transmitting UE autonomously selects the transmissionresources of an individual signal in a pool), the signal formats of thesidelink signals (e.g., the number of symbols occupied by each sidelinksignal in one subframe or the number of subframes used for transmissionof a sidelink signal), signal strengths from the BS, the transmissionpower of a sidelink UE, and so on. In sidelink communication, a mode inwhich a BS directly indicates transmission resources to a sidelinktransmitting UE is referred to as sidelink transmission mode 1, and amode in which a transmission resource area is preconfigured or the BSconfigures a transmission resource area and the UE directly selectstransmission resources is referred to as sidelink transmission mode 2.In sidelink discovery, a mode in which a BS directly indicates resourcesis referred to as Type 2, and a mode in which a UE selects transmissionresources directly from a preconfigured resource area or a resource areaindicated by the BS is referred to as Type 1.

In V2X, sidelink transmission mode 3 based on centralized scheduling andsidelink transmission mode 4 based on distributed scheduling areavailable.

FIG. 6 illustrates scheduling schemes based on these two transmissionmodes. Referring to FIG. 6, in transmission mode 3 based on centralizedscheduling of FIG. 6(a), a vehicle requests sidelink resources to a BS(S901 a), and the BS allocates the resources (S902 a). Then, the vehicletransmits a signal on the resources to another vehicle (S903 a). In thecentralized transmission, resources on another carrier may also bescheduled. In transmission mode 4 based on distributed scheduling ofFIG. 6(b), a vehicle selects transmission resources (S902 b) by sensinga resource pool, which is preconfigured by a BS (S901 b). Then, thevehicle may transmit a signal on the selected resources to anothervehicle (S903 b).

When the transmission resources are selected, transmission resources fora next packet are also reserved as illustrated in FIG. 7. In V2X,transmission is performed twice for each MAC PDU. When resources forinitial transmission are selected, resources for retransmission are alsoreserved with a predetermined time gap from the resources for theinitial transmission. The UE may identify transmission resourcesreserved or used by other UEs through sensing in a sensing window,exclude the transmission resources from a selection window, and randomlyselect resources with less interference from among the remainingresources.

For example, the UE may decode a PSCCH including information about thecycle of reserved resources within the sensing window and measure PSSCHRSRP on periodic resources determined based on the PSCCH. The UE mayexclude resources with PSCCH RSRP more than a threshold from theselection window. Thereafter, the UE may randomly select sidelinkresources from the remaining resources in the selection window.

Alternatively, the UE may measure received signal strength indication(RSSI) for the periodic resources in the sensing window and identifyresources with less interference, for example, the bottom 20 percent.After selecting resources included in the selection window from amongthe periodic resources, the UE may randomly select sidelink resourcesfrom among the resources included in the selection window. For example,when PSCCH decoding fails, the above method may be applied.

The details thereof may be found in clause 14 of 3GPP TS 3GPP TS 36.213V14.6.0, which are incorporated herein by reference.

Transmission and Reception of PSCCH

In sidelink transmission mode 1, a UE may transmit a PSCCH (sidelinkcontrol signal, SCI, etc.) on a resource configured by a BS. In sidelinktransmission mode 2, the BS may configure resources used for sidelinktransmission for the UE, and the UE may transmit the PSCCH by selectinga time-frequency resource from among the configured resources.

FIG. 8 shows a PSCCH period defined for sidelink transmission mode 1 or2.

Referring to FIG. 8, a first PSCCH (or SA) period may start in a timeresource unit apart by a predetermined offset from a specific systemframe, where the predetermined offset is indicated by higher layersignaling. Each PSCCH period may include a PSCCH resource pool and atime resource unit pool for sidelink data transmission. The PSCCHresource pool may include the first time resource unit in the PSCCHperiod to the last time resource unit among time resource unitsindicated as carrying a PSCCH by a time resource unit bitmap. In mode 1,since a time-resource pattern for transmission (T-RPT) or atime-resource pattern (TRP) is applied, the resource pool for sidelinkdata transmission may include time resource units used for actualtransmission. As shown in the drawing, when the number of time resourceunits included in the PSCCH period except for the PSCCH resource pool ismore than the number of T-RPT bits, the T-RPT may be applied repeatedly,and the last applied T-RPT may be truncated as many as the number ofremaining time resource units. A transmitting UE performs transmissionat a T-RPT position of 1 in a T-RPT bitmap, and transmission isperformed four times in one MAC PDU.

In V2X, that is, sidelink transmission mode 3 or 4, a PSCCH and data(PSSCH) are frequency division multiplexed (FDM) and transmitted, unlikesidelink communication. Since latency reduction is important in V2X inconsideration of the nature of vehicle communication, the PSCCH and dataare FDM and transmitted on the same time resources but differentfrequency resources. FIG. 9 illustrates examples of this transmissionscheme. The PSCCH and data may not be contiguous to each other asillustrated in FIG. 9(a) or may be contiguous to each other asillustrated in FIG. 9(b). A subchannel is used as the basic unit for thetransmission. The subchannel is a resource unit including one or moreRBs in the frequency domain within a predetermined time resource (e.g.,time resource unit). The number of RBs included in the subchannel, i.e.,the size of the subchannel and the starting position of the subchannelin the frequency domain are indicated by higher layer signaling.

For V2V communication, a periodic type of cooperative awareness message(CAM) and an event-triggered type of decentralized environmentalnotification message (DENM) may be used. The CAM may include dynamicstate information of a vehicle such as direction and speed, vehiclestatic data such as dimensions, and basic vehicle information such asambient illumination states, path details, etc. The CAM may be 50 to 300bytes long. In addition, the CAM is broadcast, and its latency should beless than 100 ms. The DENM may be generated upon occurrence of anunexpected incident such as a breakdown, an accident, etc. The DENM maybe shorter than 3000 bytes, and it may be received by all vehicleswithin the transmission range. The DENM may have priority over the CAM.When it is said that messages are prioritized, it may mean that from theperspective of a UE, if there are a plurality of messages to betransmitted at the same time, a message with the highest priority ispreferentially transmitted, or among the plurality of messages, themessage with highest priority is transmitted earlier in time than othermessages. From the perspective of multiple UEs, a high-priority messagemay be regarded to be less vulnerable to interference than alow-priority message, thereby reducing the probability of receptionerror. If security overhead is included in the CAM, the CAM may have alarge message size compared to when there is no security overhead.

Sidelink Congestion Control

A sidelink radio communication environment may easily become congestedaccording to increases in the density of vehicles, the amount ofinformation transfer, etc. Various methods are applicable for congestionreduction. For example, distributed congestion control may be applied.

In the distributed congestion control, a UE understands the congestionlevel of a network and performs transmission control. In this case, thecongestion control needs to be performed in consideration of thepriorities of traffic (e.g., packets).

Specifically, each UE may measure a channel busy ratio (CBR) and thendetermine the maximum value (CRlimitk) of a channel occupancy ratio(CRk) that can be occupied by each traffic priority (e.g., k) accordingto the CBR. For example, the UE may calculate the maximum value(CRlimitk) of the channel occupancy ratio for each traffic prioritybased on CBR measurement values and a predetermined table. If traffichas a higher priority, the maximum value of the channel occupancy ratiomay increase.

The UE may perform the congestion control as follows. The UE may limitthe sum of the channel occupancy ratios of traffic with a priority ksuch that the sum does not exceed a predetermined value, where k is lessthan i. According to this method, the channel occupancy ratios oftraffic with low priorities are further restricted.

Besides, the UE may use methods such as control of the magnitude oftransmission power, packet drop, determination of retransmission ornon-retransmission, and control of the size of a transmission RB (MCSadjustment).

5G Use Cases

Three key requirement areas of 5G (e.g., NR) include (1) enhanced mobilebroadband (eMBB), (2) massive machine type communication (mMTC), and (3)ultra-reliable and low latency communications (URLLC).

Some use cases may require multiple dimensions for optimization, whileothers may focus only on one key performance indicator (KPI). 5Gsupports such diverse use cases in a flexible and reliable way.

eMBB goes far beyond basic mobile Internet access and covers richinteractive work, media and entertainment applications in the cloud oraugmented reality (AR). Data is one of the key drivers for 5G and in the5G era, we may for the first time see no dedicated voice service. In 5G,voice is expected to be handled as an application program, simply usingdata connectivity provided by a communication system. The main driversfor an increased traffic volume are the increase in the size of contentand the number of applications requiring high data rates. Streamingservices (audio and video), interactive video, and mobile Internetconnectivity will continue to be used more broadly as more devicesconnect to the Internet. Many of these applications require always-onconnectivity to push real time information and notifications to users.Cloud storage and applications are rapidly increasing for mobilecommunication platforms. This is applicable for both work andentertainment. Cloud storage is one particular use case driving thegrowth of uplink data rates. 5G will also be used for remote work in thecloud which, when done with tactile interfaces, requires much lowerend-to-end latencies in order to maintain a good user experience.Entertainment, for example, cloud gaming and video streaming, is anotherkey driver for the increasing need for mobile broadband capacity.Entertainment will be very essential on smart phones and tabletseverywhere, including high mobility environments such as trains, carsand airplanes. Another use case is augmented reality (AR) forentertainment and information search, which requires very low latenciesand significant instant data volumes.

One of the most expected 5G use cases is the functionality of activelyconnecting embedded sensors in every field, that is, mMTC. It isexpected that there will be 20.4 billion potential Internet of things(IoT) devices by 2020. In industrial IoT, 5G is one of areas that playkey roles in enabling smart city, asset tracking, smart utility,agriculture, and security infrastructure.

URLLC includes services which will transform industries withultra-reliable/available, low latency links such as remote control ofcritical infrastructure and self-driving vehicles. The level ofreliability and latency are vital to smart-grid control, industrialautomation, robotics, drone control and coordination, and so on.

Now, multiple 5G use cases will be described in detail.

5G may complement fiber-to-the home (FTTH) and cable-based broadband (ordata-over-cable service interface specifications (DOCSIS)) as a means ofproviding streams at data rates of hundreds of megabits per second togiga bits per second. Such a high speed is required for TV broadcasts ator above a resolution of 4K (6K, 8K, and higher) as well as virtualreality (VR) and AR. VR and AR applications mostly include immersivesport games. A special network configuration may be required for aspecific application program. For VR games, for example, game companiesmay have to integrate a core server with an edge network server of anetwork operator in order to minimize latency.

The automotive sector is expected to be a very important new driver for5G, with many use cases for mobile communications for vehicles. Forexample, entertainment for passengers requires simultaneous highcapacity and high mobility mobile broadband, because future users willexpect to continue their good quality connection independent of theirlocation and speed. Other use cases for the automotive sector are ARdashboards. These display overlay information on top of what a driver isseeing through the front window, identifying objects in the dark andtelling the driver about the distances and movements of the objects. Inthe future, wireless modules will enable communication between vehiclesthemselves, information exchange between vehicles and supportinginfrastructure and between vehicles and other connected devices (e.g.,those carried by pedestrians). Safety systems may guide drivers onalternative courses of action to allow them to drive more safely andlower the risks of accidents. The next stage will be remote-controlledor self-driving vehicles. These require very reliable, very fastcommunication between different self-driving vehicles and betweenvehicles and infrastructure. In the future, self-driving vehicles willexecute all driving activities, while drivers are focusing on trafficabnormality elusive to the vehicles themselves. The technicalrequirements for self-driving vehicles call for ultra-low latencies andultra-high reliability, increasing traffic safety to levels humanscannot achieve.

Smart cities and smart homes, often referred to as smart society, willbe embedded with dense wireless sensor networks. Distributed networks ofintelligent sensors will identify conditions for cost- andenergy-efficient maintenance of the city or home. A similar setup can bedone for each home, where temperature sensors, window and heatingcontrollers, burglar alarms, and home appliances are all connectedwirelessly. Many of these sensors are typically characterized by lowdata rate, low power, and low cost, but for example, real time highdefinition (HD) video may be required in some types of devices forsurveillance.

The consumption and distribution of energy, including heat or gas, isbecoming highly decentralized, creating the need for automated controlof a very distributed sensor network. A smart grid interconnects suchsensors, using digital information and communications technology togather and act on information. This information may include informationabout the behaviors of suppliers and consumers, allowing the smart gridto improve the efficiency, reliability, economics and sustainability ofthe production and distribution of fuels such as electricity in anautomated fashion. A smart grid may be seen as another sensor networkwith low delays.

The health sector has many applications that may benefit from mobilecommunications. Communications systems enable telemedicine, whichprovides clinical health care at a distance. It helps eliminate distancebarriers and may improve access to medical services that would often notbe consistently available in distant rural communities. It is also usedto save lives in critical care and emergency situations. Wireless sensornetworks based on mobile communication may provide remote monitoring andsensors for parameters such as heart rate and blood pressure.

Wireless and mobile communications are becoming increasingly importantfor industrial applications. Wires are expensive to install andmaintain, and the possibility of replacing cables with reconfigurablewireless links is a tempting opportunity for many industries. However,achieving this requires that the wireless connection works with asimilar delay, reliability and capacity as cables and that itsmanagement is simplified. Low delays and very low error probabilitiesare new requirements that need to be addressed with 5G.

Finally, logistics and freight tracking are important use cases formobile communications that enable the tracking of inventory and packageswherever they are by using location-based information systems. Thelogistics and freight tracking use cases typically require lower datarates but need wide coverage and reliable location information.

Next-generation communication systems may support various use cases, forexample, communication services for autonomous driving vehicles, smartcars, or connected cars. For these services, each vehicle may exchangeinformation as a communication-capable UE. Specifically, depending onsituations, each vehicle may be assisted by a BS or select resources forcommunication and then exchange messages with another UE with noassistance from the BS. The details and/or embodiments of the presentdisclosure may be considered as one proposed method, and any combinationof details and/or embodiments may also be considered as a new proposedmethod. In addition, it is apparent that the details shall not belimited only to an embodiment of the present disclosure nor be limitedonly to a specific system. All parameters, all operations, anycombination of parameters and/or operations, the application of aspecific parameter and/or operation, and/or the application of anycombination of parameters and/or operations may be configured (orpreconfigured) by the BS for the UE through higher layer signalingand/or physical layer signaling or may be predefined in the system.Additionally, each detail of the present disclosure may be defined asone operation mode, and the BS may configure (or preconfigure) theoperation mode for the UE through higher layer signaling and/or physicallayer signaling to enable the UE to operate in the correspondingoperation mode. In this document, a transmission time interval (TTI) maycorrespond to various length units such as a sub-slot/slot/subframe, abasic transmission unit, and so on. The UE may correspond to varioustypes of devices such as a vehicle, a pedestrian UE, and so on.

Embodiment

The present disclosure proposes a method of preventing resourcefragmentation. Specifically, the present disclosure proposes a method ofpreventing and/or mitigating resource fragmentation, i.e., a phenomenonthat transmission of a large packet is disturbed when a specific UEpartially occupies resource(s) in a scheduling mode in which UEsautonomously select resources for direct communication therebetween.

In a mode where UEs autonomously select resources for directcommunication therebetween, i.e., device-to-device (D2D) communication(e.g., sidelink transmission mode 2, sidelink transmission mode 4,distributed scheduling mode, etc.), the resource fragmentation mayoccur. The resource fragmentation may mean a phenomenon that a UEtransmitting a small packet occupies several resources indiscreetly sothat a UE intending to transmit a large packet fails to occupycontiguous resources therefor. In particular, in-band emission (IBE) mayoccur in D2D communication due to non-linearity in the RF circuit of theUE. Thus, to prevent the occurrence of the IBE, the UE may need toselect contiguous resources in the frequency domain when selecting radioresources. Further, if the UE selects contiguous resources in thefrequency domain, the number of bits required for resource allocationmay be reduced as well. When a channel is transmitted on a frequencyresource, a weak noise signal may be transmitted on other frequencyresources except the frequency resource. This is called in-bandtransmission power.

As described above, the resource fragmentation may occur in the modewhere UEs select contiguous resources in the frequency domain for D2Dcommunication and autonomously select time frequency resources. As aresult, a UE having a large packet to transmit may fail to select atransmission resource because there are no contiguous resources in thefrequency domain even though the absolute amount of radio resources issufficient.

The UE may autonomously select contiguous resources in the frequencydomain. The UE may select the resources according to sensing results,select the resources in a random manner, or select the resources basedon other mechanisms. The other mechanisms may include a method by whichanother UE (e.g., a road side unit (RSU)) indicates the resources or amethod by which a receiving UE indicates candidate resources.

The UE may select a transmission resource on a continuous frequencyresource group basis. In this case, a continuous frequency resourcegroup is referred to as a subchannel That is, the UE may select thetransmission resource on a subchannel basis. When a plurality ofsubchannels are selected, contiguous subchannels may be selected. Inanother example, when one subchannel is mapped to physical frequencyresources, one logical subchannel or a plurality of subchannels may bemapped to non-contiguous frequency resources.

When the UE autonomously selects a transmission resource, the UE maysignal the selected transmission resource to a neighboring UE in acontrol signal. The neighboring UE may recognize which frequencyresources other UEs use by decoding control signals.

FIG. 10 is a flowchart illustrating an embodiment of the presentdisclosure.

The amount of frequency resources available for each subchannel may belimited. The network (e.g., BS, eNB, gNB, etc.). The network maytransmit the size of a packet available for each subchannel, the size ofa subchannel, the range of packet sizes, and/or the range of subchannelsizes to the UE through physical layer signaling or higher layersignaling. When the UE is out of the coverage of the network (e.g.,out-of-coverage UE), the above-described parameters may be predefined.For example, when the UE uses a subchannel with a specific size, if theindex of the subchannel is more than or equal to a first threshold andless than a second threshold, the UE may be configured not to use thecorresponding subchannel to prevent the resource fragmentation. Theamount of frequency resources that can be allocated for each subchannelmay be limited. For example, it is assumed that there are 6 subchannelsand the 6 subchannels are indexed from 0 to 5 in the frequency domain.In this case, if the UE uses only one subchannel, the UE may not usesubchannel indices #3 and #4.

Referring to FIG. 10, a method of transmitting a signal by a UE in awireless communication system according to an embodiment of the presentdisclosure may include: selecting, by the UE, a transmission resource(S1001); and transmitting, by the UE, the signal on the selectedtransmission resource to another UE (S1002). The transmission resourcemay include a first transmission resource region for transmitting afirst signal and a second transmission resource region for transmittinga second signal, wherein the second transmission resource region may begreater than the first transmission resource region. The first andsecond transmission resource regions may be mapped to differentsubchannel indices, and the first transmission resource region may beallocated to the edges of a frequency region for transmitting the firstand second signals. The first signal may be a narrowband signal, and thesecond signal may be a wideband signal.

The first transmission resource region may be mapped to a subchannelindex greater than a first threshold or smaller than a second threshold,and the second transmission resource region may be mapped to asubchannel index smaller than or equal to the first threshold andgreater than or equal to the second threshold. The first threshold isgreater than the second threshold.

Regarding that the first transmission resource region is allocated tothe edges of the frequency region for transmitting the first and secondsignals, the first transmission resource region may be mapped to aminimum subchannel index and a maximum subchannel index, and the secondtransmission resource region may be mapped to a subchannel index exceptthe minimum and maximum subchannel indices. For example, the first andlast indices among allocated subchannel indices may be regarded asresource edges. Thus, narrowband transmission may be performed only onresources corresponding to the first and last indices, and widebandtransmission may be performed between the first and last indices (orbetween the second and second last indices). For example, whensubchannel indices #0 to #5 are allocated, the narrowband transmissionmay be performed only in subchannel indices #0 and #5, and the widebandtransmission may be performed in subchannel indices #0 to #5 (orsubchannel indices #1 to #4). The narrowband transmission may be allowedin some edge resources among sidelink frequency resources, and thewideband transmission may be allowed in all subchannels. As anothermethod, the wideband transmission may be allowed when the subchannelindex is low, and the narrowband transmission may be allowed when thesubchannel index is more than or equal to a predetermined threshold.That is, a resource region for the wideband transmission may bedifferentiated from a resource region for the narrowband transmission.Accordingly, the present disclosure has technical effects in that itprovides a wireless communication system where a UE configured withwideband transmission easily secures a transmission resource bypreventing other UEs from selecting resources indiscreetly.

When wideband transmission (for which the subchannel size is greaterthan or equal to a predetermined value) is indicated by a specific UE, anarrowband transmission UE that uses (reserves) a region overlappingwith the indicated wideband transmission may i) drop narrowbandtransmission or ii) reselect a resource for the narrowband transmissionand then perform the narrowband transmission on the reselected resource.To this end, a UE transmitting a packet having a predetermined size ormore (e.g., wideband transmission UE) may configure a time gap with apredetermined length between control signal transmission and data signaltransmission. In this case, a UE that applies the configured time gapmay transmit a control signal before a data signal. That is, for a casein which the size of a transmitted packet is more than or equal to apredetermined threshold or the size of a frequency resource for signaltransmission (e.g., subchannel) is more than or equal to a predeterminedthreshold, the time gap between control and data signals may bepreconfigured, or the network (e.g., BS, eNB, gNB, etc.) may indicateinformation about the time gap to the UE through physical layersignaling and/or higher layer signaling. Referring to FIG. 11, anembodiment of the present disclosure may include: receiving, by atransmitting UE, control information indicating a time gap from a BS(S1101); and transmitting, by the transmitting UE to another UE, awideband signal to which the time gap indicated by the received controlinformation is applied (S1102).

In this case, the information about the time gap may include the timegap between control and data signals configured for each packet size (orrange) or for each subchannel size (or range). For out-of-networkcoverage UEs, the time gap may be predetermined. A wideband transmissionUE may perform transmission by applying the time gap between the PSCCHand PSSCH so that a narrowband transmission UE may efficiently detect(check) that narrowband transmission overlaps with widebandtransmission. According to this method, resources may be selected moreflexibly compared to other proposed methods.

Time and frequency resources may divided into a plurality of resourceregions, and the size of a subchannel available for each resource regionmay be limited. In this method, resource regions are semi-persistentlydivided depending on the size of a packet to be transmitted. Forexample, sidelink frequency resources may be divided into a plurality ofresource regions, and the size of a subchannel available for eachresource region may be limited. In this case, a resource region fornarrowband transmission may be configured at the edges of the sidelinkfrequency resources, and a resource region for wideband transmission maybe configured at the center of the sidelink frequency resources. Here,if the size of resources for a packet (or for transmitting the packet)(e.g., subchannel) is less than a prescribed threshold, it may beregarded as narrowband transmission. If the size of resources for apacket (or for transmitting the packet) (e.g., subchannel) is more thanor equal to the prescribed threshold, it may be regarded as widebandtransmission. For example, referring to the signal transmission of S1002of FIG. 10, if the size of the resource for transmitting the signal ismore than or equal to a third threshold, the signal may be transmittedas the second signal in the second resource region. If the size of theresource for transmitting the signal is less than the third threshold,the signal may be transmitted as the first signal in the first resourceregion.

The above method may reduce the sensing complexity of the UE by dividingresource regions. However, if there is no packet with a specific size,some resources may be wasted because resources are dividedsemi-persistently. To prevent the resource waste, the network (e.g., BS,eNB, gNB, etc.) may configure a specific resource region such that itoverlaps with another resource region. For example, wideband signaltransmission and/or narrowband signal transmission may be performedselectively (transmitted or dropped) in the overlapping resource regionby detecting whether there is a UE employing the specific resourceregion and/or whether the specific resource region is used. In anotherexample, resource reselection for the wideband signal transmissionand/or narrowband signal transmission may be performed based on whetherthere is a UE employing the specific resource region and/or whether thespecific resource region is used.

The above descriptions are summarized as follows.

Method 1) The amount of frequency resources available for eachsubchannel may be limited. In this case, the network may signal the sizeof a packet available for each subchannel, the size of a subchannel, therange of packet sizes, and/or the range of subchannel sizes throughphysical layer signaling or higher layer signaling. For anout-of-coverage UE (when the UE is out of the coverage of the network),these parameters may be predefined. For example, when the UE uses asubchannel with a specific size, if the index of the subchannel is morethan or equal to a first threshold and less than a second threshold, theUE may be configured not to use the corresponding subchannel to preventthe resource fragmentation. In other words, the amount of frequencyresources that can be allocated for each subchannel may be limited. Forexample, it is assumed that there are 6 subchannels and the 6subchannels are indexed from 0 to 5 in the frequency domain. In thiscase, if the UE uses only one subchannel, the UE may not use subchannelindices #3 and #4. According to this method, the following operation maybe implemented. For example, narrowband transmission may be allowed insome edge resources among sidelink frequency resources, and widebandtransmission may be allowed in all subchannels. As another method,wideband transmission may be allowed when the subchannel index is low,and the narrowband transmission may be allowed when the subchannel indexis more than or equal to a predetermined threshold. According to thismethod, when the UE is configured with wideband transmission, the UE mayeasily secures a transmission resource because other UEs are prohibitedfrom selecting resources indiscreetly.

Method 2) When wideband transmission (for which the subchannel size isgreater than or equal to a predetermined value) is indicated by aspecific UE, a narrowband transmission UE that uses/reserves a regionoverlapping with the corresponding wideband transmission may droptransmission or perform resource reselection. To this end, a UEtransmitting a packet having a predetermined size or more may configurea time gap with a predetermined length between control and data signalsand then transmit the control signal first. That is, when the size of apacket is more than or equal to a predetermined threshold or the size ofa subchannel is more than or equal to a predetermined threshold, thetime gap between control and data signals may be preconfigured.Alternatively, the network may indicate the time gap between control anddata signals for each packet size (or range) or for each subchannel size(or range) through physical layer signaling and/or higher layersignaling. This value may be predetermined when the UE is out of thenetwork coverage. According to this method, resources may be selectedmore flexibly compared to other proposed methods.

Method 3) Time and frequency resources may divided into a plurality ofresource regions, and the size of a subchannel available for eachresource region may be limited. In this method, resource regions aresemi-persistently divided depending on the size of a packet to betransmitted. For example, sidelink frequency resources may be dividedinto a plurality of resource regions, and the size of a subchannelavailable for each resource region may be limited. In this case, aresource region for narrowband transmission may be configured close tothe edges of the sidelink frequency resources (when the subchannel sizeis less than a predetermined threshold or when the packet size is lessthan a predetermined threshold), and a resource region for widebandtransmission may be configured close to the center of the sidelinkfrequency resources. This method may reduce the sensing complexity ofthe UE by dividing resource regions. However, if there is no packet witha specific size, some resources may be wasted because resources aredivided semi-persistently. To prevent the resource waste, the networkmay configure a specific resource region such that it overlaps withanother resource region. In this case, wideband signal transmissionand/or narrowband signal transmission may be performed selectively(transmitted or dropped) in the overlapping resource region by detectingwhether there is a UE employing the specific resource region and/orwhether the specific resource region is used. In another example,resource reselection for the wideband signal transmission and/ornarrowband signal transmission may be performed based on whether thereis a UE employing the specific resource region and/or whether thespecific resource region is used.

Example of Communication System to which the Present Disclosure isApplied

The various descriptions, functions, procedures, proposals, methods,and/or operation flowcharts of the present disclosure described hereinmay be applied to, but not limited to, various fields requiring wirelesscommunication/connectivity (e.g., 5G) between devices.

More specific examples will be described below with reference to thedrawings. In the following drawings/description, like reference numeralsdenote the same or corresponding hardware blocks, software blocks, orfunction blocks, unless otherwise specified.

FIG. 12 illustrates a communication system 1 applied to the presentdisclosure. Referring to FIG. 12, the communication system 1 applied tothe present disclosure includes wireless devices, BSs, and a network. Awireless device is a device performing communication using radio accesstechnology (RAT) (e.g., 5G NR (or New RAT) or LTE), also referred to asa communication/radio/5G device. The wireless devices may include, notlimited to, a robot 100 a, vehicles 100 b-1 and 100 b-2, an extendedreality (XR) device 100 c, a hand-held device 100 d, a home appliance100 e, an IoT device 100 f, and an artificial intelligence (AI)device/server 400. For example, the vehicles may include a vehiclehaving a wireless communication function, an autonomous driving vehicle,and a vehicle capable of vehicle-to-vehicle (V2V) communication. Herein,the vehicles may include an unmanned aerial vehicle (UAV) (e.g., adrone). The XR device may include an augmented reality (AR)/virtualreality (VR)/mixed reality (MR) device and may be implemented in theform of a head-mounted device (HMD), a head-up display (HUD) mounted ina vehicle, a television (TV), a smartphone, a computer, a wearabledevice, a home appliance, a digital signage, a vehicle, a robot, and soon. The hand-held device may include a smartphone, a smart pad, awearable device (e.g., a smart watch or smart glasses), and a computer(e.g., a laptop). The home appliance may include a TV, a refrigerator, awashing machine, and so on. The IoT device may include a sensor, a smartmeter, and so on. For example, the BSs and the network may beimplemented as wireless devices, and a specific wireless device 200 amay operate as a BS/network node for other wireless devices.

The wireless devices 100 a to 100 f may be connected to the network 300via the BSs 200. An AI technology may be applied to the wireless devices100 a to 100 f, and the wireless devices 100 a to 100 f may be connectedto the AI server 400 via the network 300. The network 300 may beconfigured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g.,NR) network. Although the wireless devices 100 a to 100 f maycommunicate with each other through the BSs 200/network 300, thewireless devices 100 a to 100 f may perform direct communication (e.g.,sidelink communication) with each other without intervention of theBSs/network. For example, the vehicles 100 b-1 and 100 b-2 may performdirect communication (e.g. V2V/vehicle-to-everything (V2X)communication). The IoT device (e.g., a sensor) may perform directcommunication with other IoT devices (e.g., sensors) or other wirelessdevices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, and 150 c may beestablished between the wireless devices 100 a to 100 f/BS 200 andbetween the BSs 200. Herein, the wireless communication/connections maybe established through various RATs (e.g., 5G NR) such as UL/DLcommunication 150 a, sidelink communication 150 b (or, D2Dcommunication), or inter-BS communication (e.g. relay or integratedaccess backhaul (IAB)). Wireless signals may be transmitted and receivedbetween the wireless devices, between the wireless devices and the BSs,and between the BSs through the wireless communication/connections 150a, 150 b, and 150 c. For example, signals may be transmitted and receivedon various physical channels through the wirelesscommunication/connections 150 a, 150 b and 150 c. To this end, at leasta part of various configuration information configuring processes,various signal processing processes (e.g., channel encoding/decoding,modulation/demodulation, and resource mapping/demapping), and resourceallocation processes, for transmitting/receiving wireless signals, maybe performed based on the various proposals of the present disclosure.

Example of Wireless Device to which the Present Disclosure is Applied

FIG. 13 illustrates wireless devices applicable to the presentdisclosure.

Referring to FIG. 13, a first wireless device 100 and a second wirelessdevice 200 may transmit wireless signals through a variety of RATs(e.g., LTE and NR). {The first wireless device 100 and the secondwireless device 200} may correspond to {the wireless device 100 x andthe BS 200} and/or {the wireless device 100 x and the wireless device100 x} of FIG. 12.

The first wireless device 100 includes one or more processors 102 andone or more memories 104, and may further include one or moretransceivers 106 and/or one or more antennas 108. The processor 102 maybe configured to control the memory 104 and/or the transceiver 106 toimplement the descriptions, functions, procedures, proposals, methodsand/or operation flowcharts disclosed in the present document. Forexample, the processor 102 may be configured to implement at least oneoperation for the methods described above in relation to FIG. 10 or FIG.11. For example, the processor 102 may be configured to select atransmission resource and control the transceiver 106 and/or antenna 108to transmit a signal on the selected transmission resource to anotherUE. The transmission resource may include a first transmission resourceregion for transmission of a first signal and a second transmissionresource region for transmission of a second signal, wherein the secondtransmission resource region is greater than the first transmissionresource region. The first and second transmission resource regions maybe mapped to different subchannel indices. The first transmissionresource region may be allocated to the edges of a frequency region fortransmitting the first and second signals.

In addition, the processor 102 may generate a first information/signalby processing information within the memory 104 and then transmit awireless signal including the first information/signal through thetransceiver 106. In addition, the processor 102 may receive a wirelesssignal including a second information/signal through the transceiver 106and then save information obtained from the signal processing of thesecond information/signal to the memory 104. The memory 104 may beconnected to the processor 102 and store various information related tooperations of the processor 102. For example, the memory 104 may storesoftware codes including commands for performing some or all of theprocesses controlled by the processor 102 or executing the descriptions,functions, procedures, methods and/or operation flowcharts disclosed inthe present document. Here, the processor 102 and the memory 104 may bea part of a communication modem/circuit/chip designed to implement thewireless communication technology (e.g., LTE, NR). The transceiver 106may be connected to the processor 102 and transmit and/or receivewireless signals through one or more antennas 108. The transceiver 106may include a transmitter and/or receiver. It is able to use thetransceiver 106 mixed with a Radio Frequency (RF) unit. In the presentdisclosure, a wireless device may mean a communicationmodem/circuit/chip.

The second wireless device 200 may include one or more processors 202and one or more memories 204, and further include one or moretransceivers 206 and/or one or more antennas 208. The processor(s) 202may control the memory(s) 204 and/or the transceiver(s) 206 and may beconfigured to implement the descriptions, functions, procedures,proposals, methods, and/or operation flowcharts disclosed in thisdocument. For example, the processor(s) 202 may process information inthe memory(s) 204 to generate third information/signals and thentransmit wireless signals including the third information/signalsthrough the transceiver(s) 206. The processor(s) 202 may receivewireless signals including fourth information/signals through thetransceiver(s) 106 and then store information obtained by processing thefourth information/signals in the memory(s) 204. The memory(s) 204 maybe connected to the processor(s) 202 and store various pieces ofinformation related to operations of the processor(s) 202. For example,the memory(s) 204 may store software code including instructions forperforming all or a part of processes controlled by the processor(s) 202or for performing the descriptions, functions, procedures, proposals,methods, and/or operation flowcharts disclosed in this document. Theprocessor(s) 202 and the memory(s) 204 may be a part of a communicationmodem/circuit/chip designed to implement RAT (e.g., LTE or NR). Thetransceiver(s) 206 may be connected to the processor(s) 202 and transmitand/or receive wireless signals through the one or more antennas 208.Each of the transceiver(s) 206 may include a transmitter and/or areceiver. The transceiver(s) 206 may be interchangeably used with RFunit(s). In the present disclosure, the wireless device may be acommunication modem/circuit/chip.

Now, hardware elements of the wireless devices 100 and 200 will bedescribed in greater detail. One or more protocol layers may beimplemented by, not limited to, one or more processors 102 and 202. Forexample, the one or more processors 102 and 202 may implement one ormore layers (e.g., functional layers such as physical (PHY), mediumaccess control (MAC), radio link control (RLC), packet data convergenceprotocol (PDCP), RRC, and service data adaptation protocol (SDAP)). Theone or more processors 102 and 202 may generate one or more protocoldata units (PDUs) and/or one or more service data Units (SDUs) accordingto the descriptions, functions, procedures, proposals, methods, and/oroperation flowcharts disclosed in this document. The one or moreprocessors 102 and 202 may generate messages, control information, data,or information according to the descriptions, functions, procedures,proposals, methods, and/or operation flowcharts disclosed in thisdocument and provide the messages, control information, data, orinformation to one or more transceivers 106 and 206. The one or moreprocessors 102 and 202 may generate signals (e.g., baseband signals)including PDUs, SDUs, messages, control information, data, orinformation according to the descriptions, functions, procedures,proposals, methods, and/or operation flowcharts disclosed in thisdocument and provide the generated signals to the one or moretransceivers 106 and 206. The one or more processors 102 and 202 mayreceive the signals (e.g., baseband signals) from the one or moretransceivers 106 and 206 and acquire the PDUs, SDUs, messages, controlinformation, data, or information according to the descriptions,functions, procedures, proposals, methods, and/or operation flowchartsdisclosed in this document.

The one or more processors 102 and 202 may be referred to ascontrollers, microcontrollers, microprocessors, or microcomputers. Theone or more processors 102 and 202 may be implemented by hardware,firmware, software, or a combination thereof. For example, one or moreapplication specific integrated circuits (ASICs), one or more digitalsignal processors (DSPs), one or more digital signal processing devices(DSPDs), one or more programmable logic devices (PLDs), or one or morefield programmable gate arrays (FPGAs) may be included in the one ormore processors 102 and 202. The descriptions, functions, procedures,proposals, methods, and/or operation flowcharts disclosed in thisdocument may be implemented using firmware or software, and the firmwareor software may be configured to include the modules, procedures, orfunctions. Firmware or software configured to perform the descriptions,functions, procedures, proposals, methods, and/or operation flowchartsdisclosed in this document may be included in the one or more processors102 and 202 or may be stored in the one or more memories 104 and 204 andexecuted by the one or more processors 102 and 202. The descriptions,functions, procedures, proposals, methods, and/or operation flowchartsdisclosed in this document may be implemented using firmware or softwarein the form of code, an instruction, and/or a set of instructions.

The one or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 and store various types of data, signals,messages, information, programs, code, instructions, and/or commands Theone or more memories 104 and 204 may be configured to include read-onlymemories (ROMs), random access memories (RAMs), electrically erasableprogrammable read-only memories (EPROMs), flash memories, hard drives,registers, cash memories, computer-readable storage media, and/orcombinations thereof. The one or more memories 104 and 204 may belocated at the interior and/or exterior of the one or more processors102 and 202. The one or more memories 104 and 204 may be connected tothe one or more processors 102 and 202 through various technologies suchas wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, controlinformation, and/or wireless signals/channels, mentioned in the methodsand/or operation flowcharts of this document, to one or more otherdevices. The one or more transceivers 106 and 206 may receive user data,control information, and/or wireless signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperation flowcharts disclosed in this document, from one or more otherdevices. For example, the one or more transceivers 106 and 206 may beconnected to the one or more processors 102 and 202 and transmit andreceive wireless signals. For example, the one or more processors 102and 202 may perform control so that the one or more transceivers 106 and206 may transmit user data, control information, or wireless signals toone or more other devices. The one or more processors 102 and 202 mayperform control so that the one or more transceivers 106 and 206 mayreceive user data, control information, or wireless signals from one ormore other devices. The one or more transceivers 106 and 206 may beconnected to the one or more antennas 108 and 208 and the one or moretransceivers 106 and 206 may be configured to transmit and receive userdata, control information, and/or wireless signals/channels, mentionedin the descriptions, functions, procedures, proposals, methods, and/oroperation flowcharts disclosed in this document, through the one or moreantennas 108 and 208. In this document, the one or more antennas may bea plurality of physical antennas or a plurality of logical antennas(e.g., antenna ports). The one or more transceivers 106 and 206 mayconvert received wireless signals/channels from RF band signals intobaseband signals in order to process received user data, controlinformation, and wireless signals/channels using the one or moreprocessors 102 and 202. The one or more transceivers 106 and 206 mayconvert the user data, control information, and wirelesssignals/channels processed using the one or more processors 102 and 202from the baseband signals into the RF band signals. To this end, the oneor more transceivers 106 and 206 may include (analog) oscillators and/orfilters.

Example of Signal Processing Circuit to which the Present Disclosure isApplied

FIG. 14 is a block diagram illustrating a signal processing circuit 1000for transmission (Tx) signals to which one embodiment of the presentdisclosure can be applied.

Referring to FIG. 14, the signal processing circuit 1000 may include ascrambler 1010, a modulator 1020, a layer mapper 1030, a precoder 1040,a resource mapper 1050, and a signal generator 1060. Theoperations/functions shown in FIG. 14 may be performed by the processors102 and 202 and/or the transceivers 106 and 206 shown in FIG. 13,without being limited thereto. Hardware elements shown in FIG. 14 may beimplemented by the processors 102 and 202 and/or the transceivers 106and 206 shown in FIG. 13. For example, the blocks 1010 to 1060 may beimplemented by the processors 102 and 202. In addition, the blocks 1010to 1050 may be implemented by the processors 102 and 202 shown in FIG.13, and the block 1060 may be implemented by the transceivers 106 and206 shown in FIG. 13.

The codeword may be converted into a radio signal (or a radio frequency(RF) signal) through the signal processing circuit 1000 shown in FIG.14. Here, the codeword may be a coded bit sequence of an informationblock. The information block may include a transmission (Tx) block(e.g., UL-SCH transmission block, and/or DL-SCH transmission block). Theradio signal may be transmitted through various physical channels (e.g.,PUSCH, and PDSCH).

In more detail, the codeword may be converted into a bit sequencescrambled by the scrambler 1010. The scramble sequence used for suchscrambling may be generated based on an initialization value, and theinitialization value may include ID information of a wireless device,etc. The scrambled bit-sequence may be modulated into a modulated symbolsequence by the demodulator 1020. The modulation scheme may includepi/2-BPSK(pi/2-Binary Phase Shift Keying), m-PSK(m-Phase Shift Keying),m-QAM(m-Quadrature Amplitude Modulation), etc. The complex modulatedsymbol sequence may be mapped to one or more transmission (Tx) layers bythe layer mapper 1030. Modulated symbols of the respective Tx layers maybe mapped (precoded) to the corresponding antenna port(s) by theprecoder 1040. The output value (z) of the precoder 1040 may be obtainedby multiplying the output value (y) of the layer mapper 1030 by the(N×M) precoding matrix (W). In this case, N is the number of antennaports, and M is the number of Tx layers. In this case, the precoder 1040may perform precoding after transform precoding (e.g., DFT transform) isperformed on the complex modulated symbols. In this case, the precoder1040 may perform precoding without performing transform precoding.

The resource mapper 1050 may map the modulated symbols of the respectiveantenna ports to time-frequency resources. The time-frequency resourcesmay include a plurality of symbols (e.g., CP-OFDMA symbol andDFT-s-OFDMA symbol) in the time domain, and may include a plurality ofsubcarriers in the frequency domain. The signal generator 1060 maygenerate radio signals from the mapped modulated symbols, and thegenerated radio signals may be transferred to other devices through therespective antennas. To this end, the signal generator 1060 may includean Inverse Fast Fourier Transform (IFFT) module, a Cyclic Prefix (CP)inserter, a Digital-to-Analog Converter (DAC), a frequency uplinkconverter, etc.

The signal processing steps for reception (Rx) signals in the wirelessdevice may be arranged in the reverse order of the signal processingsteps 1010 to 1060 shown in FIG. 14. For example, the wireless devices100 and 200 (shown in FIG. 4) may receive radio signals from the outsidethrough the antenna ports/transceivers. The received radio signals maybe converted into a baseband signal through a signal restorer. To thisend, the signal restorer may include a frequency downlink converter, ananalog-to-digital converter (ADC), a CP remover, and a Fast FourierTransform (FFT) module. Thereafter, the baseband signal may be restoredto the codeword after passing through the resource demapper process, thepostcoding process, the demodulation process, and the descramblingprocess. The codeword may be restored to an original information blockthrough decoding. Therefore, the signal processing circuit (not shown)for Rx signals may include a signal restorer, a resource demapper, apostcoder, a demodulator, a descrambler, and a decoder.

Example of Wireless Device to which the Present Disclosure is Applied

FIG. 15 illustrates another example of a wireless device applied to thepresent disclosure. The wireless device may be implemented in variousforms according to a use case/service (refer to FIGS. 12, 16, 17 and18).

Referring to FIG. 15, a wireless device 100/200 corresponds to thewireless device 100/200 shown in FIG. 13 and may include variouselements, components, units/parts and/or modules. For example, thewireless device 100/200 may include a communication unit 110, a controlunit 120, a memory unit 130 and an additional component 140. Thecommunication unit 110 may include a communication circuit 112 andtransceiver(s) 114. For example, the communication circuit 112 mayinclude one or more processors 102/202 and/or one or more memories104/204 shown in FIG. 13. For example, the transceiver(s) 114 mayinclude one or more transceivers 106/206 and/or one or more antennas108/208. The control unit 120 is electrically connected to thecommunication unit 110, the memory unit 130 and the additional component140 and controls overall operations of the wireless device. For example,based on the program/code/command/information stored in the memory unit130, the control unit 120 may control electrical/mechanical operationsof the wireless device. In addition, the control unit 120 may transmitinformation stored in the memory unit 130 to an external device (e.g.,another communication device) through the communication unit 110 via awire/wireless interface or save information received from an externaldevice (e.g., another communication device) through the communicationunit 110 via the wire/wireless interface to the memory unit 130. Forexample, the control unit 120 may be configured to implement at leastone operation for the methods described with reference to FIG. 10 orFIG. 11. For example, the control unit 120 may be configured to select atransmission resource and control the communication unit 110 to transmita signal on the selected transmission resource to another UE. Thetransmission resource may include a first transmission resource regionfor transmission of a first signal and a second transmission resourceregion for transmission of a second signal, wherein the secondtransmission resource region is greater than the first transmissionresource region. The first and second transmission resource regions maybe mapped to different subchannel indices. The first transmissionresource region may be allocated to the edges of a frequency region fortransmitting the first and second signals.

The additional components 140 may be configured in various mannersaccording to type of the wireless device. For example, the additionalcomponents 140 may include at least one of a power unit/battery,input/output (I/O) unit, a driving unit, and a computing unit. Thewireless device may be implemented in the form of, not limited to, therobot (100 a of FIG. 12), the vehicles (100 b-1 and 100 b-2 of FIG. 12),the XR device (100 c of FIG. 12), the hand-held device (100 d of FIG.12), the home appliance (100 e of FIG. 12), the IoT device (100 f ofFIG. 12), a digital broadcasting terminal, a hologram device, a publicsafety device, an MTC device, a medical device, a FinTech device (or afinance device), a security device, a climate/environment device, the AIserver/device (400 of FIG. 12), the BSs (200 of FIG. 12), a networknode, or the like. The wireless device may be mobile or fixed accordingto a use case/service.

In FIG. 15, all of the various elements, components, units/portions,and/or modules in the wireless devices 100 and 200 may be connected toeach other through a wired interface or at least a part thereof may bewirelessly connected through the communication unit 110. For example, ineach of the wireless devices 100 and 200, the control unit 120 and thecommunication unit 110 may be connected by wire and the control unit 120and first units (e.g., 130 and 140) may be wirelessly connected throughthe communication unit 110. Each element, component, unit/portion,and/or module in the wireless devices 100 and 200 may further includeone or more elements. For example, the control unit 120 may beconfigured with a set of one or more processors. For example, thecontrol unit 120 may be configured with a set of a communication controlprocessor, an application processor, an electronic control unit (ECU), agraphical processing unit, and a memory control processor. In anotherexample, the memory 130 may be configured with a RAM, a dynamic RAM(DRAM), a ROM, a flash memory, a volatile memory, a non-volatile memory,and/or a combination thereof.

The implementation example of FIG. 15 will hereinafter be described withreference to the attached drawings.

Example of Hand-held device to which the Present Disclosure is Applied

FIG. 16 is a block diagram illustrating a hand-held device 100 to whichanother embodiment of the present disclosure can be applied. Thehand-held device may include a smartphone, a tablet (also called asmartpad), a wearable device (e.g., a smartwatch or smart glasses), anda portable computer (e.g., a laptop). The hand-held device 100 may bereferred to as a mobile station (MS), a user terminal (UT), a mobilesubscriber station (MSS), a subscriber station (SS), an advanced mobilestation (AMS), or a wireless terminal (WT).

Referring to FIG. 16, the hand-held device 100 may include an antennaunit 108, a communication unit 110, a control unit 120, a memory unit130, a power supply unit 140 a, an interface unit 140 b, and aninput/output (I/O) unit 140 c. The antenna unit 108 may be configured asa part of the communication unit 110. The blocks 110 to 130/140 a to 140c correspond to the blocks 110 to 130/140 of FIG. 15, respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from another wireless device and a BS. Thecontrol unit 120 may perform various operations by controlling elementsof the hand-held device 100. The control unit 120 may include anapplication processor (AP). The memory unit 130 may storedata/parameters/programs/code/commands required for operation of thehand-held device 100. Further, the memory unit 130 may storeinput/output data/information. The power supply unit 140 a may supplypower to the hand-held device 100, and include a wired/wireless chargingcircuit and a battery. The interface unit 140 b may support connectionbetween the hand-held device and other external devices. The interfaceunit 140 b may include various ports (e.g., an audio I/O port and avideo I/O port) for connection to external devices. The I/O unit 140 cmay receive or output video information/signal, audioinformation/signal, data, and/or user-input information. The I/O unit140 c may include a camera, a microphone, a user input unit, a display140 d, a speaker, and/or a haptic module.

For example, for data communication, the I/O unit 140 c may acquireinformation/signals (e.g., touch, text, voice, images, and video)received from the user and store the acquired information/signals in thememory unit 130. The communication unit 110 may convert theinformation/signals into radio signals and transmit the radio signalsdirectly to another device or to a BS. Further, the communication unit110 may receive a radio signal from another device or a BS and thenrestore the received radio signal to original information/signal. Therestored information/signal may be stored in the memory unit 130 andoutput in various forms (e.g., text, voice, an image, video, and ahaptic effect) through the I/O unit 140 c.

Example of Vehicle or Autonomous Driving Vehicle to which the PresentDisclosure is Applied

FIG. 17 illustrates a vehicle or an autonomous driving vehicle appliedto the present disclosure. The vehicle or autonomous driving vehicle maybe implemented as a mobile robot, a car, a train, a manned/unmannedaerial vehicle (AV), a ship, or the like.

Referring to FIG. 17, a vehicle or autonomous driving vehicle 100 mayinclude an antenna unit 108, a communication unit 110, a control unit120, a driving unit 140 a, a power supply unit 140 b, a sensor unit 140c, and an autonomous driving unit 140 d. The antenna unit 108 may beconfigured as a part of the communication unit 110. The blocks110/130/140 a to 140 d correspond to the blocks 110/130/140 of FIG. 16,respectively.

The communication unit 110 may transmit and receive signals (e.g., data,control signals, etc.) with external devices such as another vehicle, abase station (e.g., a base station, a road side unit, etc.), a serverand the like. The control unit 120 may perform various operations bycontrolling elements of a vehicle or autonomous vehicle 100. The controlunit 120 may include an Electronic Control Unit (ECU). For example, thecontrol unit 120 may be configured to implement at least one operationfor the methods described above in relation to FIG. 10 or FIG. 11. Forexample, the control unit 120 may be configured to select a transmissionresource and control the communication unit 110 to transmit a signal onthe selected transmission resource to another UE. The transmissionresource may include a first transmission resource region fortransmission of a first signal and a second transmission resource regionfor transmission of a second signal, wherein the second transmissionresource region is greater than the first transmission resource region.The first and second transmission resource regions may be mapped todifferent subchannel indices. The first transmission resource region maybe allocated to the edges of a frequency region for transmitting thefirst and second signals.

The driving unit 140 a may enable the vehicle or the autonomous drivingvehicle 100 to drive on a road. The driving unit 140 a may include anengine, a motor, a powertrain, a wheel, a brake, a steering device, andso on. The power supply unit 140 b may supply power to the vehicle orthe autonomous driving vehicle 100 and include a wired/wireless chargingcircuit, a battery, and so on. The sensor unit 140 c may acquireinformation about a vehicle state, ambient environment information, userinformation, and so on. The sensor unit 140 c may include an inertialmeasurement unit (IMU) sensor, a collision sensor, a wheel sensor, aspeed sensor, a slope sensor, a weight sensor, a heading sensor, aposition module, a vehicle forward/backward sensor, a battery sensor, afuel sensor, a tire sensor, a steering sensor, a temperature sensor, ahumidity sensor, an ultrasonic sensor, an illumination sensor, a pedalposition sensor, and so on. The autonomous driving unit 140 d mayimplement technology for maintaining a lane on which the vehicle isdriving, technology for automatically adjusting speed, such as adaptivecruise control, technology for autonomously driving along a determinedpath, technology for driving by automatically setting a route if adestination is set, and the like.

For example, the communication unit 110 may receive map data, trafficinformation data, and so on from an external server. The autonomousdriving unit 140 d may generate an autonomous driving route and adriving plan from the obtained data. The control unit 120 may controlthe driving unit 140 a such that the vehicle or autonomous drivingvehicle 100 may move along the autonomous driving route according to thedriving plan (e.g., speed/direction control). During autonomous driving,the communication unit 110 may aperiodically/periodically acquire recenttraffic information data from the external server and acquiresurrounding traffic information data from neighboring vehicles. Duringautonomous driving, the sensor unit 140 c may obtain information about avehicle state and/or surrounding environment information. The autonomousdriving unit 140 d may update the autonomous driving route and thedriving plan based on the newly obtained data/information. Thecommunication unit 110 may transfer information about a vehicleposition, the autonomous driving route, and/or the driving plan to theexternal server. The external server may predict traffic informationdata using AI technology based on the information collected fromvehicles or autonomous driving vehicles and provide the predictedtraffic information data to the vehicles or the autonomous drivingvehicles.

Example of Augmented Reality (AR)/Virtual Reality (VR) and Vehicle

FIG. 18 illustrates a vehicle or an autonomous driving vehicle 100 towhich another embodiment of the present disclosure can be applied. Thevehicle or autonomous driving vehicle may be configured as atransportation means, a train, an aircraft, a ship, or the like.

Referring to FIG. 18, the vehicle 100 may include a communication unit110, a control unit 120, a memory unit 130, an I/O unit 140 a, and aposition measurement unit 140 b. The blocks 110 to 130/140 a to 140 ccorrespond to the blocks 110 to 130/140 of FIG. 16, respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from external devices such as other vehiclesor BSs. The control unit 120 may perform various operations bycontrolling elements of the vehicle 100. The memory unit 130 may storedata/parameters/programs/code/commands required for operation of thehand-held device 100. The I/O unit 140 a may output AR/VR objects basedon information stored in the memory unit 130. The I/O unit 140 a mayinclude a head-up display (HUD). The position measurement unit 140 b mayacquire position information of the vehicle 100. The positioninformation of the vehicle 100 may include absolute position informationof the vehicle 100, position information within a vehicle travelinglane, acceleration information, position information about peripheralvehicles, etc. The position measurement unit 140 b may include varioussensors.

For example, the communication unit 110 of the vehicle 100 may receivemap data, traffic information data, and so on from an external server,and may store the received information in the memory unit 130. Theposition measurement unit 140 b may acquire position information of thevehicle 100 through GPS and various sensors, and may store the acquiredinformation in the memory unit 130. The controller 130 may generate avirtual object based on map information, traffic information, vehicleposition information, etc. The I/O unit 140 b may display the virtualobject on a windshield of the vehicle, as represented by 1410 and 1420.In addition, the controller 120 may determine whether the vehicle 100 isnormally driving in the traveling lane based on vehicle positioninformation. If the vehicle 100 abnormally deviates from the travelinglane, the control unit 140 may display a warning message on thewindshield of the vehicle 100. In addition, the control unit 120 maybroadcast a warning message indicating an abnormal driving state to theperipheral vehicles through the communication unit 110. In accordancewith various situations, the controller 120 may control thecommunication unit 110 to transmit vehicle position information,information about abnormal driving, and information about an abnormalvehicle state to the organizations concerned.

The embodiments of the present disclosure described above arecombinations of elements and features of the present disclosure. Theelements or features may be considered selective unless otherwisementioned. Each element or feature may be practiced without beingcombined with other elements or features. Further, an embodiment of thepresent disclosure may be constructed by combining parts of the elementsand/or features. Operation orders described in embodiments of thepresent disclosure may be rearranged. Some constructions of any oneembodiment may be included in another embodiment and may be replacedwith corresponding constructions of another embodiment. It is obvious tothose skilled in the art that claims that are not explicitly cited ineach other in the appended claims may be presented in combination as anembodiment of the present disclosure or included as a new claim by asubsequent amendment after the application is filed.

The embodiments of the present disclosure have been described above,focusing on the signal transmission and reception relationship between aUE and a BS. The signal transmission and reception relationship isextended to signal transmission and reception between a UE and a relayor between a BS and a relay in the same manner or a similar manner Aspecific operation described as performed by a BS may be performed by anupper node of the BS. Namely, it is apparent that, in a networkcomprised of a plurality of network nodes including a BS, variousoperations performed for communication with a UE may be performed by theBS, or network nodes other than the BS. The term BS may be replaced withthe term fixed station, Node B, enhanced Node B (eNode B or eNB), accesspoint, and so on. Further, the term UE may be replaced with the termterminal, mobile station (MS), mobile subscriber station (MSS), and soon.

The embodiments of the present disclosure may be achieved by variousmeans, for example, hardware, firmware, software, or a combinationthereof. In a hardware configuration, the methods according to theembodiments of the present disclosure may be achieved by one or moreapplication specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, controllers, microcontrollers, microprocessors,etc.

In a firmware or software configuration, the embodiments of the presentdisclosure may be implemented in the form of a module, a procedure, afunction, etc. For example, software code may be stored in a memory unitand executed by a processor. The memory unit is located at the interioror exterior of the processor and may transmit and receive data to andfrom the processor via various known means.

Those skilled in the art will appreciate that the present disclosure maybe carried out in other specific ways than those set forth hereinwithout departing from the spirit and essential characteristics of thepresent disclosure. The above embodiments are therefore to be construedin all aspects as illustrative and not restrictive. The scope of thedisclosure should be determined by the appended claims and their legalequivalents, not by the above description, and all changes coming withinthe meaning and equivalency range of the appended claims are intended tobe embraced therein.

INDUSTRIAL APPLICABILITY

The above-mentioned embodiments of the present disclosure are applicableto various mobile communication systems.

1. A method of transmitting a signal by a user equipment (UE) in awireless communication system, the method comprising: selecting, by theUE, a transmission resource; and transmitting the signal on the selectedtransmission resource to another UE, wherein the transmission resourceincludes a first transmission resource region for transmission of afirst signal and a second transmission resource region for transmissionof a second signal, wherein the second transmission resource region isgreater than the first transmission resource region, wherein the firstand second transmission resource regions are mapped to differentsubchannel indices, and wherein the first transmission resource regionis allocated to edges of a frequency region for transmitting the firstand second signals.
 2. The method of claim 1, wherein the firsttransmission resource region is mapped to a subchannel index greaterthan a first threshold or smaller than a second threshold, wherein thesecond transmission resource region is mapped to a subchannel indexsmaller than or equal to the first threshold and greater than or equalto the second threshold, and wherein the first threshold is greater thanthe second threshold.
 3. The method of claim 1, wherein the firsttransmission resource region is mapped to a minimum subchannel index anda maximum subchannel index, and wherein the second transmission resourceregion is mapped to a subchannel index except the minimum and maximumsubchannel indices.
 4. The method of claim 1, wherein transmitting thesignal comprises: based on that an amount of resources for transmittingthe signal is greater than or equal to a third threshold, transmittingthe signal as the second signal in the second resource region; and basedon that the amount of resources for transmitting the signal is smallerthan the third threshold, transmitting the signal as the first signal inthe first resource region.
 5. The method of claim 1, further comprising,based on that the first transmission resource region overlaps with thesecond transmission resource region, dropping the transmission of thefirst signal or reselecting the transmission resource.
 6. The method ofclaim 1, further comprising configuring and transmitting a time gapbetween control and data signals for the second signal.
 7. The method ofclaim 1, wherein the first and second transmission resource regions areconfigured within a resource pool for transmission of a sidelink signal.8. The method of claim 1, wherein the first signal is a narrowbandsignal, and wherein the second signal is a wideband signal.
 9. A userequipment (UE) for transmitting a signal in a wireless communicationsystem, the UE comprising: a transceiver; and a processor configured to:select a transmission resource; and transmit the signal on the selectedtransmission resource to another UE, wherein the transmission resourceincludes a first transmission resource region for transmission of afirst signal and a second transmission resource region for transmissionof a second signal, wherein the second transmission resource region isgreater than the first transmission resource region, wherein the firstand second transmission resource regions are mapped to differentsubchannel indices, and wherein the first transmission resource regionis allocated to edges of a frequency region for transmitting the firstand second signals.
 10. The UE of claim 9, wherein the UE is configuredto communicate with at least one of a mobile terminal, a network, or anautonomous driving vehicle other than an apparatus.
 11. The UE of claim9, wherein the UE is configured to implement at least one advanceddriver assistance system (ADAS) function based on a signal forcontrolling movement of the UE.
 12. The UE of claim 9, wherein the UE isconfigured to switch a driving mode of an apparatus from an autonomousdriving mode to a manual driving mode or from the manual driving mode tothe autonomous driving mode upon receipt of a user input.
 13. The UE ofclaim 9, wherein the UE is configured to perform autonomous drivingbased on external object information, and wherein the external objectinformation includes at least one of information about presence of anobject, information about a location of the object, information about adistance between the UE and the object, or information about a relativespeed of the UE with respect to the object.